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stm32f0-discovery/lib/src/peripherals/stm32f0xx_comp.c

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/**
******************************************************************************
* @file stm32f0xx_comp.c
* @author MCD Application Team
* @version V1.0.0
* @date 23-March-2012
* @brief This file provides firmware functions to manage the following
* functionalities of the comparators (COMP1 and COMP2) peripheral:
* + Comparators configuration
* + Window mode control
*
* @verbatim
*
===============================================================================
##### How to use this driver #####
===============================================================================
[..]
The device integrates two analog comparators COMP1 and COMP2:
(+) The non inverting input is set to PA1 for COMP1 and to PA3
for COMP2.
(+) The inverting input can be selected among: DAC_OUT1,
1/4 VREFINT, 1/2 VERFINT, 3/4 VREFINT, VREFINT,
I/O (PA0 for COMP1 and PA2 for COMP2)
(+) The COMP output is internally is available using COMP_GetOutputLevel()
and can be set on GPIO pins: PA0, PA6, PA11 for COMP1
and PA2, PA7, PA12 for COMP2
(+) The COMP output can be redirected to embedded timers (TIM1, TIM2
and TIM3)
(+) The two comparators COMP1 and COMP2 can be combined in window
mode and only COMP1 non inverting (PA1) can be used as non-
inverting input.
(+) The two comparators COMP1 and COMP2 have interrupt capability
with wake-up from Sleep and Stop modes (through the EXTI controller).
COMP1 and COMP2 outputs are internally connected to EXTI Line 21
and EXTI Line 22 respectively.
##### How to configure the comparator #####
===============================================================================
[..]
This driver provides functions to configure and program the Comparators
of all STM32F0xx devices.
[..] To use the comparator, perform the following steps:
(#) Enable the SYSCFG APB clock to get write access to comparator
register using RCC_APB2PeriphClockCmd(RCC_APB2Periph_SYSCFG, ENABLE);
(#) Configure the comparator input in analog mode using GPIO_Init()
(#) Configure the comparator output in alternate function mode
using GPIO_Init() and use GPIO_PinAFConfig() function to map the
comparator output to the GPIO pin
(#) Configure the comparator using COMP_Init() function:
(++) Select the inverting input
(++) Select the output polarity
(++) Select the output redirection
(++) Select the hysteresis level
(++) Select the power mode
(#) Enable the comparator using COMP_Cmd() function
(#) If required enable the COMP interrupt by configuring and enabling
EXTI line in Interrupt mode and selecting the desired sensitivity
level using EXTI_Init() function. After that enable the comparator
interrupt vector using NVIC_Init() function.
@endverbatim
*
******************************************************************************
* @attention
*
* <h2><center>&copy; COPYRIGHT 2012 STMicroelectronics</center></h2>
*
* Licensed under MCD-ST Liberty SW License Agreement V2, (the "License");
* You may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
*
* http://www.st.com/software_license_agreement_liberty_v2
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
******************************************************************************
*/
/* Includes ------------------------------------------------------------------*/
#include "stm32f0xx_comp.h"
/** @addtogroup STM32F0xx_StdPeriph_Driver
* @{
*/
/** @defgroup COMP
* @brief COMP driver modules
* @{
*/
/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
/* CSR register Mask */
#define COMP_CSR_CLEAR_MASK ((uint32_t)0x00003FFE)
/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
/* Private function prototypes -----------------------------------------------*/
/* Private functions ---------------------------------------------------------*/
/** @defgroup COMP_Private_Functions
* @{
*/
/** @defgroup COMP_Group1 Initialization and Configuration functions
* @brief Initialization and Configuration functions
*
@verbatim
===============================================================================
##### Initialization and Configuration functions #####
===============================================================================
@endverbatim
* @{
*/
/**
* @brief Deinitializes COMP peripheral registers to their default reset values.
* @note Deinitialization can't be performed if the COMP configuration is locked.
* To unlock the configuration, perform a system reset.
* @param None
* @retval None
*/
void COMP_DeInit(void)
{
COMP->CSR = ((uint32_t)0x00000000); /*!< Set COMP_CSR register to reset value */
}
/**
* @brief Initializes the COMP peripheral according to the specified parameters
* in COMP_InitStruct
* @note If the selected comparator is locked, initialization can't be performed.
* To unlock the configuration, perform a system reset.
* @note By default, PA1 is selected as COMP1 non inverting input.
* To use PA4 as COMP1 non inverting input call COMP_SwitchCmd() after COMP_Init()
* @param COMP_Selection: the selected comparator.
* This parameter can be one of the following values:
* @arg COMP_Selection_COMP1: COMP1 selected
* @arg COMP_Selection_COMP2: COMP2 selected
* @param COMP_InitStruct: pointer to an COMP_InitTypeDef structure that contains
* the configuration information for the specified COMP peripheral.
*
* @retval None
*/
void COMP_Init(uint32_t COMP_Selection, COMP_InitTypeDef* COMP_InitStruct)
{
uint32_t tmpreg = 0;
/* Check the parameters */
assert_param(IS_COMP_ALL_PERIPH(COMP_Selection));
assert_param(IS_COMP_INVERTING_INPUT(COMP_InitStruct->COMP_InvertingInput));
assert_param(IS_COMP_OUTPUT(COMP_InitStruct->COMP_Output));
assert_param(IS_COMP_OUTPUT_POL(COMP_InitStruct->COMP_OutputPol));
assert_param(IS_COMP_HYSTERESIS(COMP_InitStruct->COMP_Hysteresis));
assert_param(IS_COMP_MODE(COMP_InitStruct->COMP_Mode));
/*!< Get the COMP_CSR register value */
tmpreg = COMP->CSR;
/*!< Clear the COMP1SW1, COMPx_IN_SEL, COMPx_OUT_TIM_SEL, COMPx_POL, COMPx_HYST and COMPx_PWR_MODE bits */
tmpreg &= (uint32_t) ~(COMP_CSR_CLEAR_MASK<<COMP_Selection);
/*!< Configure COMP: inverting input, output redirection, hysteresis value and power mode */
/*!< Set COMPxINSEL bits according to COMP_InitStruct->COMP_InvertingInput value */
/*!< Set COMPxOUTSEL bits according to COMP_InitStruct->COMP_Output value */
/*!< Set COMPxPOL bit according to COMP_InitStruct->COMP_OutputPol value */
/*!< Set COMPxHYST bits according to COMP_InitStruct->COMP_Hysteresis value */
/*!< Set COMPxMODE bits according to COMP_InitStruct->COMP_Mode value */
tmpreg |= (uint32_t)((COMP_InitStruct->COMP_InvertingInput | COMP_InitStruct->COMP_Output |
COMP_InitStruct->COMP_OutputPol | COMP_InitStruct->COMP_Hysteresis |
COMP_InitStruct->COMP_Mode)<<COMP_Selection);
/*!< Write to COMP_CSR register */
COMP->CSR = tmpreg;
}
/**
* @brief Fills each COMP_InitStruct member with its default value.
* @param COMP_InitStruct: pointer to an COMP_InitTypeDef structure which will
* be initialized.
* @retval None
*/
void COMP_StructInit(COMP_InitTypeDef* COMP_InitStruct)
{
COMP_InitStruct->COMP_InvertingInput = COMP_InvertingInput_1_4VREFINT;
COMP_InitStruct->COMP_Output = COMP_Output_None;
COMP_InitStruct->COMP_OutputPol = COMP_OutputPol_NonInverted;
COMP_InitStruct->COMP_Hysteresis = COMP_Hysteresis_No;
COMP_InitStruct->COMP_Mode = COMP_Mode_UltraLowPower;
}
/**
* @brief Enable or disable the COMP peripheral.
* @note If the selected comparator is locked, enable/disable can't be performed.
* To unlock the configuration, perform a system reset.
* @param COMP_Selection: the selected comparator.
* This parameter can be one of the following values:
* @arg COMP_Selection_COMP1: COMP1 selected
* @arg COMP_Selection_COMP2: COMP2 selected
* @param NewState: new state of the COMP peripheral.
* This parameter can be: ENABLE or DISABLE.
* @note When enabled, the comparator compares the non inverting input with
* the inverting input and the comparison result is available
* on comparator output.
* @note When disabled, the comparator doesn't perform comparison and the
* output level is low.
* @retval None
*/
void COMP_Cmd(uint32_t COMP_Selection, FunctionalState NewState)
{
/* Check the parameters */
assert_param(IS_COMP_ALL_PERIPH(COMP_Selection));
assert_param(IS_FUNCTIONAL_STATE(NewState));
if (NewState != DISABLE)
{
/* Enable the selected COMP peripheral */
COMP->CSR |= (uint32_t) (1<<COMP_Selection);
}
else
{
/* Disable the selected COMP peripheral */
COMP->CSR &= (uint32_t)(~((uint32_t)1<<COMP_Selection));
}
}
/**
* @brief Close or Open the SW1 switch.
* @note This switch is solely intended to redirect signals onto high
* impedance input, such as COMP1 non-inverting input (highly resistive switch)
* @param NewState: New state of the analog switch.
* This parameter can be: ENABLE or DISABLE.
* @note When enabled, the SW1 is closed; PA1 is connected to PA4
* @note When disabled, the SW1 switch is open; PA1 is disconnected from PA4
* @retval None
*/
void COMP_SwitchCmd(FunctionalState NewState)
{
/* Check the parameter */
assert_param(IS_FUNCTIONAL_STATE(NewState));
if (NewState != DISABLE)
{
/* Close SW1 switch */
COMP->CSR |= (uint32_t) (COMP_CSR_COMP1SW1);
}
else
{
/* Open SW1 switch */
COMP->CSR &= (uint32_t)(~COMP_CSR_COMP1SW1);
}
}
/**
* @brief Return the output level (high or low) of the selected comparator.
* @note The output level depends on the selected polarity.
* If the polarity is not inverted:
* @note -Comparator output is low when the non-inverting input is at a lower
* voltage than the inverting input
* @note -Comparator output is high when the non-inverting input is at a higher
* voltage than the inverting input
* @note If the polarity is inverted:
* @note -Comparator output is high when the non-inverting input is at a lower
* voltage than the inverting input
* @note -Comparator output is low when the non-inverting input is at a higher
* voltage than the inverting input
* @param COMP_Selection: the selected comparator.
* This parameter can be one of the following values:
* @arg COMP_Selection_COMP1: COMP1 selected
* @arg COMP_Selection_COMP2: COMP2 selected
* @retval Returns the selected comparator output level: low or high.
*
*/
uint32_t COMP_GetOutputLevel(uint32_t COMP_Selection)
{
uint32_t compout = 0x0;
/* Check the parameters */
assert_param(IS_COMP_ALL_PERIPH(COMP_Selection));
/* Check if selected comparator output is high */
if ((COMP->CSR & (COMP_CSR_COMP1OUT<<COMP_Selection)) != 0)
{
compout = COMP_OutputLevel_High;
}
else
{
compout = COMP_OutputLevel_Low;
}
/* Return the comparator output level */
return (uint32_t)(compout);
}
/**
* @}
*/
/** @defgroup COMP_Group2 Window mode control function
* @brief Window mode control function
*
@verbatim
===============================================================================
##### Window mode control function #####
===============================================================================
@endverbatim
* @{
*/
/**
* @brief Enables or disables the window mode.
* In window mode, COMP1 and COMP2 non inverting inputs are connected
* together and only COMP1 non inverting input (PA1) can be used.
* param NewState: new state of the window mode.
* This parameter can be :
* @arg ENABLE: COMP1 and COMP2 non inverting inputs are connected together.
* @arg DISABLE: OMP1 and COMP2 non inverting inputs are disconnected.
* @retval None
*/
void COMP_WindowCmd(FunctionalState NewState)
{
/* Check the parameters */
assert_param(IS_FUNCTIONAL_STATE(NewState));
if (NewState != DISABLE)
{
/* Enable the window mode */
COMP->CSR |= (uint32_t) COMP_CSR_WNDWEN;
}
else
{
/* Disable the window mode */
COMP->CSR &= (uint32_t)(~COMP_CSR_WNDWEN);
}
}
/**
* @}
*/
/** @defgroup COMP_Group3 COMP configuration locking function
* @brief COMP1 and COMP2 configuration locking function
* COMP1 and COMP2 configuration can be locked each separately.
* Unlocking is performed by system reset.
*
@verbatim
===============================================================================
##### Configuration Lock function #####
===============================================================================
@endverbatim
* @{
*/
/**
* @brief Lock the selected comparator (COMP1/COMP2) configuration.
* @note Locking the configuration means that all control bits are read-only.
* To unlock the comparator configuration, perform a system reset.
* @param COMP_Selection: selects the comparator to be locked
* This parameter can be a value of the following values:
* @arg COMP_Selection_COMP1: COMP1 configuration is locked.
* @arg COMP_Selection_COMP2: COMP2 configuration is locked.
* @retval None
*/
void COMP_LockConfig(uint32_t COMP_Selection)
{
/* Check the parameter */
assert_param(IS_COMP_ALL_PERIPH(COMP_Selection));
/* Set the lock bit corresponding to selected comparator */
COMP->CSR |= (uint32_t) (COMP_CSR_COMP1LOCK<<COMP_Selection);
}
/**
* @}
*/
/**
* @}
*/
/**
* @}
*/
/**
* @}
*/
/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/
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